Before users can contribute to projects, they need to request access to a language team. If there is an inactive co-ordinator, then these requests will not be dealt with and users will abandon Zanata. This also demands unnecessary overhead to administrators for non-maintained languages.
Add an option to allow automatic granting of translator privileges, if there is no need to tightly control them.
I think this depends on the workflow chosen for the individual project. Some projects (i.e. community ones) might want to open their doors to anyone who wishes to contribute. Other projects might want to carefully vet who contributes translations. Perhaps a project-wide setting to allow/prevent this behaviour is the way to go.
I think a feature to enable blacklisting of domains for signup might be a good idea